Plant-protection chemical composition for the treatment of timber, and disinfection of soils, characterised in that it comprises at least one INORGANIC DERIVATIVE OF CHLORINE, and more particularly a HYPOCHLORITE or a CHLORIDE. Processes selective for the "RULE OF THE ART" which the treatment of timber and the disinfection of soils by the OVICIDAL, BACTERICIDAL, DISINFECTANT and FUNGICIDAL function have become, in that a chemical composition is used.